Erosive potencial of energy drinks on the dentine surface

Coordenação de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)

Análise comparativa dos métodos MQL, MQL/Água e convencional na retificação cilíndrica do aço ABNT 52100, com rebolo de óxido de alumínio

Pós-graduação em Engenharia Mecânica - FEB

Efeito de nanofilmes depositados a plasma na resistência de união de um cimento resinoso a uma cerâmica à base de zircônia

Pós-graduação em Odontologia Restauradora - ICT

Dentifrício fluoretado suplementado com hexametafosfato de sódio sobre o processo de desmineralização do esmalte: estudos in vitro e in situ

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Métodos preventivos em primeiro molar permanente de crianças com experiência de cárie dentária: estudo clínico comparativo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Contribuição ao estudo do desgaste de bedames na usinagem de ligas de alumínio-silício

Pós-graduação em Engenharia Mecânica - FEIS

Influence of different toothpaste abrasives on the bristle end-rounding quality of toothbrushes

ObjectivesTo evaluate the influence of different toothpaste abrasives on the bristle wear and bristle tip morphology of toothbrushes with different degrees of hardness.Material and methodsNinety samples of bovine incisor teeth were used in this study. The samples were randomly divided into three groups according to the bristle hardness of the toothbrush used: soft bristles (S); extra-soft bristles (ES); hard bristles (H). The toothbrushes of each group were randomly divided into six subgroups with five toothbrushes each, according to the abrasive of the toothpaste used in the simulation: Negative control (distilled water); toothpaste 1 (silica); toothpaste 2 (hydrated silica); toothpaste 3 (calcium carbonate, calcium bicarbonate and silica); toothpaste 4 (tetrapotassium pyrophosphate, silica and titanium dioxide); toothpaste 5 (calcium carbonate). The samples were placed in a toothbrushing simulating machine that simulating three months of brushing. The toothbrush bristles were evaluated by the bristle wear index, and the bristle tips morphology was evaluated by the bristle tip morphology index.ResultsThe ES brush presented the highest bristle wear among the toothbrushes. Additionally, the S brushes showed better morphology of the bristles followed by ES and H brushes. The type of abrasive only influenced the bristle tip morphology of the ES brushes. The toothpaste 3 induced the worse bristle tip morphology than all the other toothpastes.ConclusionsDifferent abrasives have influence only on the bristle tip morphology of the ES brushes.

Plasma Treatment to Improve the Surface Properties of Recycled Post-Consumer PVC

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Intraoral fluoride levels after use of conventional and high-fluoride dentifrices

This study aimed to evaluate saliva and plaque as indicators of intraoral fluoride (F) levels after the use of conventional and high-fluoride dentifrices.Subjects were randomly assigned to brush their teeth with conventional (1000 ppm F), high-fluoride (5000 ppm F), and placebo dentifrices (fluoride free) for 10 days, following a double-blind, crossover protocol. Saliva and plaque samples were collected on the morning of the 5(th) and 10th days, respectively at 1 and 12 h after brushing, and analyzed with an ion-selective electrode after HMDS-facilitated diffusion. Data were analyzed by two-way repeated measures ANOVA, Tukey's test and Spearman's correlation coefficient (p < 0.05).Plaque and salivary F levels were significantly increased after the use of conventional and high-fluoride dentifrices when compared to values obtained for placebo, except plaque 12 h after the use of conventional dentifrice. A positive and significant correlation was found between fluoride concentrations in plaque and saliva for both times of sample collection.Both indicators assessed were able to detect significant differences among treatments and between times after brushing. The use of a high-fluoride dentifrice is able to significantly increase intraoral fluoride levels throughout the day, being therefore a useful therapy for patients at high caries risk.A dentifrice with high fluoride concentration could be regarded as a useful therapy of F delivery for high caries-risk patients, since intraoral F levels were sustained throughout most of the day after using this formulation.

Erosive cola-based drinks affect the bonding to enamel surface: an in vitro study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Conventional and whitening toothpastes: Cytotoxicity, genotoxicity and effect on the enamel surface

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of Nd:YAG or Er:YAG laser surface treatment on microtensile bond strength of indirect resin composites to resin cement. Lasers surface treatment of indirect resin composites

This study evaluated the influence of the surface pretreatment of indirect resin composite (Signum, Admira Lab and Sinfony) on the microtensile bond strength of a resin cement. Sixty samples made of each brand were divided into 6 groups, according to surface treatment: (1) control; (2) controlled-air abrasion with Al2O3; (3) Er:YAG Laser 200 mJ, 10 Hz, for 10s; (4) Er: YAG Laser 300 mJ, 10 Hz, for 10 s; (5) Nd:YAG 80 mJ, S15Hz for 1 min; (6) Nd:YAG 120mJ, 15 Hz for 1 min. After treatments, all the groups received an application of 37% phosphoric acid and adhesive. The pair of blocks of the same brand were cemented to each other with dual resin cement. The blocks were sectioned to obtain resin-resin sticks (1 x1 mm) and analyzed by microtensile bond testing. The bond strength values were statistically different, irrespective of the surface treatment performed, with highest values for Sinfony (43.81 MPa) and lowest values for Signum (32.33 MPA). The groups treated with the Nd:YAG laser showed the lowest bond strength values and power did not interfere in the results, both for Nd:YAG laser and Er:YAG. Controlled-air abrasion with Al203 is an efficient surface treatment method and the use of the Nd:YAG and Er:YAG lasers reduced bond strength, irrespective of the intensity of energy used.

Antiseptic mouthwashes: in vitro antibacterial activity

Mouthwashes are used as an adjunct to tooth brushing for improving breath and preventing oral diseases. The aim of this study was to compare the in vitro Maximum Inhibitory Dilution (MID) of 3 mouthwashes with different active ingredients against mutans streptococci (MS). The products analyzed were PeriogardR, CepacolR and PlaxR Fresh Mint. Their antibacterial activity was assessed in duplicate in 96-well microtiter plates against 36 clinical isolates of MS. Each mouthwash was submitted to a serial two-fold dilution (1/2.5 to 1/5120) using double concentration of Tryptose Soy Broth with 1.0% yeast extract. The final volume in each well was 100 mL plus 5 mL of a bacterial suspension, equivalent to 107 CFU/mL. They were incubated microaerobically at 37oC for 48 hours and the MIDs determined. MID was 1/320 for PeriogardR and CepacolR, and 1/20 for PlaxR. Statistical analysis revealed that the MID of PeriogardR MID did not differ from that of CepacolR (p>0.05), and was higher than that of PlaxR (p<0.05). In conclusion, the antiseptic mouthwashes containing chlorhexidine (PeriogardR) and cetylpyridinium chloride (CepacolR) had higher in vitroantibacterial activity (MID) against MS than the antiseptic mouthwash containing triclosan (PlaxR), according to microbiological method employed.

Fluoride gel supplemented with sodium hexametaphosphate reduces enamel erosive wear in situ

This study evaluated the effect of fluoride gels, supplemented or not with sodium hexametaphosphate (HMP), on enamel erosive wear in situ. Twelve healthy volunteers wore palatal appliances containing four bovine enamel discs. Subjects were randomly allocated into four experimental phases (double-blind, crossover protocol) according to the gels: Placebo (no fluoride or HMP), 1% NaF, 2% NaF, and 1% NaF+9% HMP. Enamel discs were selected after polishing and surface hardness analysis, and treated only once with the respective gels prior to each experimental phase. Erosion (ERO) was performed by extra-oral immersion of the appliance in 0.05M citric acid, pH 3.2 (four times/day, five minutes each, 5 days). Additional abrasion (ERO+ABR) was produced on only two discs by toothbrushing with fluoridated dentifrice after ERO (four times/day, 30s, 5 days). The specimens were submitted to profilometry and hardness analysis. The results were analyzed by two-way ANOVA and the Student-Newman-Keuls test (p<0.05). The 1% NaF+9% HMP gel promoted significantly lower enamel wear for ERO compared to the other groups, being statistically lower than 1% NaF and Placebo for ERO+ABR. Similarly, the lowest values of integrated lesion area were found for 1% NaF+9% HMP and 2% NaF, respectively, for ERO and ERO+ABR. The addition of HMP to the 1% NaF gel promoted greater protective effect against ERO and ERO+ABR compared to the 1% NaF gel, achieving similar protective levels to those seen for the 2% NaF gel. Gel containing 1% NaF+9% HMP showed a high anti-erosive potential, being a safer alternative when compared to a conventional 2% NaF gel.

Effects of pH and fluoride concentration of dentifrices on fluoride levels in saliva, biofilm, and biofilm fluid in vivo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)